This overshadowing, which has threatened to mask the significance of Irene's work, is illuminated poignantly, and perhaps unintentionally, by Francis Carter Wood, writing in Science Monthly in 1938:
"Marie Curie by her chemical discovery of the element radium inaugurated what may be called modern physics, and it must have been to her a marvelous satisfaction that her daughter, Irene Joliet-Curie, has followed in her footsteps, making one discovery after another, which would render the name Curie imperishable had her mother never been famous." (1)He goes on to say, "It remains to Marie the singular distinction among women of having made the most revolutionary discovery in atomic physics."(2) Here is the paradox. We can conjecture that Irene would not have had the academic opportunities and the research opportunities to develop into one of the 20th centuries formost chemists if her mother had not paved the way for her, but the significance of her work is often overlooked in contrast to her mother's contributions to science.
Irene was born on September 12, 1897, the elder of two daughters born to Marie and Pierre Curie. Without anticipating women's lib, but simply by not questioning her ability to do so, Marie combined an active career in research with motherhood. To Marie, an important part of motherhood was orchestrating the education of her daughters. From her earliest childhood, it was clear that Irene was very intelligent and had exceptional talent in mathematics. She entered school at six. The school near the Curie home was not considered suitable so Irene began her formal education with the more challenging curriculum offered at a school on the rue Cassini, near the Observatory. At the age of ten, Irene's talents and interest in mathematics were apparent. Since there was not an appropriate school for her in all of Paris, Irene, along with nine other children of prestigious scholars studied in their own school, known as the "Cooperative" (call it " home schooling" or "alternative education"). Their teachers included Marie Curie, Paul Langevin, and Jean Perrin. Perhaps equally important to Irene's intellectual development were the ongoing conversations that she shared with her mother, to say nothing of the math puzzles that concluded the letters she received from her mother when they were separated.
Irene finished her high school education at College of Sevigne, an independent school in the center of Paris. She entered the Sorbonne in October, 1914 to prepare for a baccalaureate in mathematics and physics. Her education was interrupted by World War I. In 1916, Irene left the Sorbonne to assist her Marie Curie with the fleet of mobile x-ray facilities that helped to save the lives of so many wounded soldiers. Irene extended this work by directing the development of diagnostic x-ray facilities in military hospitals in France and Belgium. After the war, she received a Military Medal for this endeavor.
In 1918, Irene joined the staff of the Curie Institute as her mother's assistant. During this time she was also completing her doctoral dissertation on the alpha rays of polonium. She successfully defended her thesis in March, 1925.
Frederic Joliet visited the Institute in December, 1924 at which time he met with Marie at the suggestion of his mentor, Paul Langevin. Marie invited Frederick to join the institute as one of her assistants. Irene was given the job of teaching him the techniques required to work with radioactivity. Irene and Frederick were married in a civil ceremony on October 29, 1926. Their daughter Helene was born on September 17, 1927 and their son Pierre on March 12, 1932. Like her mother, Irene combined family and profession. Although both Irene and Frederick spent long hours in the laboratory, it is clear that their family was important to them. Holidays were an important time for them. Until World War II interrupted this, they were often together at their vacation home in L'Arcouest.
Irene abhorred the frivolous. Her childhood was dedicated to her studies, her adulthood to her research. For relaxation she liked to hike in the mountains, ski, or play tennis. In contrast to her sister Eve, who enjoyed dressing in the height of fashion, Irene followed her mother's pattern of dressing simply. One gets the sense that she resented wasting any resources of funds, energy, or time on fashion. The exception to this was her appearance at her Nobel Prize Ceremony. Pictures of this event reveal a beautiful, elegant woman in a long, black gown.
Irene was awarded her Nobel prize in a time of astonishing developments in atomic physics. In the preceding few years, Chadwick had identified the neutron, completing the elucidation of the triumverate of particles which compose all atoms, and which replaced the Daltonian theory of solid spherical atoms. The task of modern chemists and atomic physicists was to restore a sense of order to the atom, which at this time seemed quite vaporous and busy, having been shown, approximately three decades earlier, to contain tiny negative electrons and, several years later, relatively massive positive nuclei, all somehow avoiding each other despite their attractive natures. These particles seemed to exist in an atom which was a virtual void since, as demonstrated by Ernst Rutherford, together these particles seemed to occupy very little space. In addition, certain elements, such as radium, were seen to undergo extremely energetic emissions of particles or rays, in the process transforming themselves into other elements. Cockcroft and Walton had, weeks after the identification of the neutron, managed to realize the alchemists dream of deliberate transmutation of one element to another - a startling development, but only one of many to follow shortly within a decade.
Irene, with husband Frederic, was already busy in the field, having confirmed the discovery of the positron in 1932. For this they used gamma rays from still scarce purified samples of natural radioactive isotopes, which were first isolated by her parents, Marie and Pierre Curie. Two years later, in 1934, the availability of radioactive substances, so valuable for medical and research purposes, was to start changing dramatically. In that year, Irene and Frederic first demonstrated the creation of an 'artificially' radioactive element, an isotope, of nitrogen::
10B + 4He ------> 13N + 1nThis process was repeated with aluminum and magnesium in short order.
boron(mass 10) + alpha particle(mass 4) -->radioactive nitrogen(mass 13) + neutron
27Al + 4He ------> 30P + 1nThis discovery was to transfigure the periodic table of the time, eventually adding more than 400 radioisotopes. Through isolation and concentration of these new 'artificially' radioactive isotopes, many became available within a few years for medicine, research, and eventually weapons. Their discovery fundamentally changed our understanding of the relationships between elements, leading to an understanding of the fission of heavier elements to lighter ones, and the fusion of lighter elements to heavier ones. Surprisingly perhaps, before any of this could transpire, and the significance of this work be fully realized, Irene and Frederick Joliet-Curie were awarded the Nobel Prize in Chemistry a scant year after their work, in 1935, "for their synthesis of new radioactive elements."(3) In later years, they extended their work to the identification of the products of nuclear fission and became embroiled in the surrounding social issues concerning the uses of radioactivity.
24Mg + 4He ------> 27Si + 1n
Some scientists are theoreticians, some are experimentalists, some are superb administrators. Irene Joliet-Curie was all three. She was the director of the Curie Laboratory, a member of the Commissariat of Atomic energy, and a professor at the Sorbonne. Although she won many awards for her contributions to science, she was never admitted to the French Academy of Science. In 1911, the Insititut de France voted to maintain it's all male status. This apporved institutional policy denied a seat in the Academy to Marie Curie. This same restrictive policy would prevail for an additional four decades.
Irene was an autocrat in the laboratory, exerting the authority of her position to make sure that work done at the Institute was meticulous. Politically, she was a socialist and she demonstrated her belief in social equality on several occasions. Because of continuing frailty due to a continuing battle with tuberculosis, Irene spent most of the World War II years in a convalescent home in Switzerland. Because of concern for her for the safety of her husband and children, she did occasionally return to Paris. In 1943, she was stopped at the Swiss border when she attempted to enter the country at Porrentruy. She spent several days, with hundreds of other refugees fleeing the Nazis, sleeping on a straw mat in a communal room in a detention center. The prefect of the district found out about this and arranged to have her moved, but she refused to be given special treatment, and insisted on remaining until her release.
After the end of the war, antibiotics became available. Irene was treated with them and her health improved to some extent. It was during this period that she was detained at another border and forced to spend the night in communal facilities. In 1948, Irene planned a fund raising tour in the United States to raise money for Spanish refugees. Although she had a valid visa, it was the time of McCarthyism and red scares. Irene was forbidden entry and was kept in a detention center on Ellis Island until the French embassy in Washington could intervene.
Irene Joliet-Curie died from leukemia on March 17, 1956, still being denied membership in the French Academy of Science.
3 Farber, Eduard. Nobel Prize Winners in Chemistry. Abelard-Schumann. London, NY, Toronto. 1953. p.142.
del Regato, Juan A., M.D. Radiological Physicists. American Institute of Physics, Inc. 335 East 45 St, NY, NY. 1985.
Farber, Eduard, ed. Great Chemists. Interscience Publishers, NY, London. 1961.
Farber, Eduard. Nobel Prize Winners in Chemistry. Abelard-Schumann. London, NY, Toronto. 1953.
Jaffe, Bernard. Crucibles: the Story of Chemistry. Dover Publications, Inc. NY. fourth edition, 1976.
Pflaum, Rosalind. Grand Obsession. Doubleday, N.Y., N.Y., 1989.